激光拉曼分光计中超低杂散光的测试

本文提出了一种测试激光拉曼分光计中超低杂散光的新方法.实验结果表明,本方法的杂散光测量限可达10~(-14)量级.     

超薄反射镜支撑技术

运用有限元方法对一种超薄反射镜的多个支撑方案进行分析计算,其中包括支撑点数量及排布方式的合理选择、支撑组件的优化设计。分析结果表明:该超薄反射镜在自重下的面形精度通过多点调节能够满足要求,预示了将该支撑技术应用于超薄反射镜具有可行性,并为超薄反射镜结构在面形控制实验中实施主动调节提供了数值依据。     

A High-Power Reflector Impulse Antenna with Dual-Tem Source

There are different demands on radiation efficiency and direction pattern according to various ultra-wideband (UWB) antennas and high power applications. To obtain more radiating gain on bore-sight of paraboloidal reflector and centralized radiating direction, a novel feeding structure called dual-TEM source has been designed and applied in half-paraboloidal reflector impulse radiating antenna (IRA) applications. Simulation results proved that this proposed half-paraboloidal reflector IRA with dual-TEM source provided greater radiation performance on bore-sight as a result of the synthesized power in the aperture space of paraboloid. Moreover, lots of simulation work and comparison have been done in different feeding models to summarize a relative optimal feeding structure.     

镜像系统和镜像天线

对电荷电流体系在理想导体平面所形成的镜像系统的各物理量作了全面分析，并得出镜像天线的结果。     

A High Gain and Broadband C-Band Aperture-Coupled Patch Antenna

A aperture-coupled patch antenna is designed with parasitic elements connecting to the rectangle ring on the bottom of antenna substrate through metal vias, which lead the current induced by patch radiator to the top surface of antenna substrate. Therefore, the effective radiation is enhanced and higher gain is achieved. The bandwidth is broadened simultaneously due to the structure of aperture-coupled patch antenna with parasitic elements. Compared to the conventional aperture-coupled patch antenna, the antenna gain increases averagely 2 dB due to the novel structure. Compared to patch antenna of electromagnetic band-gap, the dimensions of novel patch antenna greatly decreases, which can be used as element in the array antenna. Two kinds manufactured antenna are both measured in an anechoic chamber. The good agreements between numerical simulation and experimental prototype have been obtained.     

二维圆柱坐标系中五角形共形网格算法

 时域有限差分（FDTD）算法求解电磁问题时，如果目标结构不能和传统网格体系共形，往往采用局部共形网格或非正交网格算法。详细讨论了二维圆柱坐标系中五角形共形网格算法，该算法能方便地对倾斜薄层媒质或电导率不均匀的倾斜媒质等复杂结构建模,并以锥形电磁脉冲天线为例，验证了该算法的有效性。     

A Novel Feeding Scheme for Bandwidth Enhancement of Suspended Planar Antenna

A suspended planar antenna with a novel feeding structure is proposed for bandwidth enhancement. This feeding structure can provide extra degrees of freedom to tune the antenna for compensating for the large inductance induced by the long feeding probe. An impedance bandwidth of 56% for VSWR<2 is obtained. Simulated and measured results are compared and good agreements are observed.     

Aqueous self-aggregates of amphiphilic zinc 3-hydroxy- and 3-methoxy-chlorins for supramolecular light-harvesting systems

Aqueous aggregates of zinc 3¹-hydroxy- and 3¹-methoxy-13¹-oxo-chlorins possessing a hydrophilic tetraoxyethylene chain were prepared. Zinc 3¹-methoxy-chlorin formed a well-ordered aggregate without intermolecular hydrogen bonding which has been widely accepted in most structural models for BChl-c, d, e aggregates in a major light-harvesting antenna of green photosynthetic bacteria, chlorosome.     

Thermally tuned optical fiber for true time delay generation

A new technique for generating a continuous range of true time delay values is introduced. Heating optical fiber in order to change the effective index of the guided mode produces time delays. A 45-m section of single-mode silica fiber is demonstrated to produce a continuous range of time delay values from 0 to 211 ps over a temperature tuning range of 50°C (30–80°C). A thermal time delay factor is introduced and found to be 0.096 ps/m°C for Corning LEAF fiber. A 7.66-m section of multimode Lucina polymer fiber is demonstrated to produce a range of time delay values from 0 to 32 ps over a temperature tuning range of 30°C (30–60°C). The thermal time delay factor for this fiber is −0.1427 ps/m°C.     

光子晶体Vlasov天线辐射特性研究

 通过在Vlasov天线口径上加装金属面，再在金属面上环绕天线口径排布金属圆柱构成光子晶体，设计出一种新型的光子晶体Vlasov天线。数值仿真及实验结果均表明，光子晶体的带隙特性改善了天线的辐射特性，使得E面上的最大增益在工作频段内平均提高了2.43 dB。